Author: Haitao Fang
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages :

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Author: Wei Zhang
Publisher:
ISBN:
Category : Carbon dioxide
Languages : en
Pages : 290

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Book Description
A systematic investigation of pitting failure of mild steel in marginally sour environments was performed with the objective of understanding and predicting the occurrence of localized corrosion. While localized corrosion can happen due to a variety of reasons, recent work has shown that mild steel was particularly susceptible to pitting in environments containing traces of H2S (ppm level in the gas phase, which equates to ppb level of dissolved O2 in the liquid phase) of H2S. Relevant research works related to localized corrosion of mild steel exposed to O2, CO2 and H2S containing aqueous environments were carefully reviewed and a critical comparison was performed, identifying experimental methodologies, common mechanisms and gaps in understanding. A comprehensive parametric study was conducted to identify the operating parameters controlling the occurrence of localized corrosion in marginally sour environments. As a result, pitting was found to occur under the following conditions: 0 mbar pH2S 0.15 mbar, pCO2 0 bar, temperature

Author: Xin Gao
Publisher:
ISBN:
Category : Acetic acid
Languages : en
Pages : 191

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Book Description
The objective of this dissertation research was to investigate initiation mechanisms for CO2 localized corrosion on mild steel, encompassing the effects of chloride, oxygen, and acetic acid. In CO2 corrosion, iron in steel will be oxidized to ferrous ions under deareated conditions. The ferrous and carbonate ions can combine to form FeCO3 and precipitate once exceeding the solubility limit. When the precipitation of FeCO3 occurs evenly on the steel surface it forms a compact and protective layer. This acts as a diffusion barrier hindering the mass transfer of electrochemical species and covers/blocks the surface making it unavailable for corrosion, which enhances the resistance of mild steel to further uniform CO2 corrosion. However, there are various scenarios where localized corrosion may occur. When the environment becomes more aggressive, the FeCO3 could be partially removed. This leads to localized regions of the bare steel surface that become exposed to the corrosive solution and, subsequently, localized corrosion could be initiated. To study CO2 localized corrosion, two-stage experiments were performed: (1) a uniform protective FeCO3 layer was first formed on a carbon steel with high initial FeCO3 saturation; (2) localized CO2 corrosion scenarios were then developed by adding additional salts (NaCl or NaClO4), oxygen or acetic acid to challenge the protective FeCO3 layer. The experiments were conducted in a two-liter glass cell with a three-electrode system, working electrode (X65 carbon steel), reference electrode (Ag/AgCl saturated electrode), and counter electrode (platinum). Electrochemical measurements (linear polarization resistance) were carried out to observe electrochemical behaviors and calculate the corrosion rates.

Author: A. M. El-Sherik
Publisher: Woodhead Publishing
ISBN: 0081012195
Category : Science
Languages : en
Pages : 928

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Book Description
Trends in Oil and Gas Corrosion Research and Technologies: Production and Transmission delivers the most up-to-date and highly multidisciplinary reference available to identify emerging developments, fundamental mechanisms and the technologies necessary in one unified source. Starting with a brief explanation on corrosion management that also addresses today's most challenging issues for oil and gas production and transmission operations, the book dives into the latest advances in microbiology-influenced corrosion and other corrosion threats, such as stress corrosion cracking and hydrogen damage just to name a few. In addition, it covers testing and monitoring techniques, such as molecular microbiology and online monitoring for surface and subsurface facilities, mitigation tools, including coatings, nano-packaged biocides, modeling and prediction, cathodic protection and new steels and non-metallics. Rounding out with an extensive glossary and list of abbreviations, the book equips upstream and midstream corrosion professionals in the oil and gas industry with the most advanced collection of topics and solutions to responsibly help solve today's oil and gas corrosion challenges. - Covers the latest in corrosion mitigation techniques, such as corrosion inhibitors, biocides, non-metallics, coatings, and modeling and prediction - Solves knowledge gaps with the most current technology and discoveries on specific corrosion mechanisms, highlighting where future research and industry efforts should be concentrated - Achieves practical and balanced understanding with a full spectrum of subjects presented from multiple academic and world-renowned contributors in the industry

Author: Azman Jalar
Publisher: Springer Nature
ISBN: 9811918511
Category : Technology & Engineering
Languages : en
Pages : 255

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Book Description
This book gathers the latest research, innovations, and applications in the field of corrosion prevention and control, as presented by leading national and international academics, researchers, engineers, and postgraduate students at the AWAM International Conference on Civil Engineering 2022 (AICCE’22), held 7th International Corrosion Prevention Symposium for Research Scholars (CORSYM 2021), held as a virtual conference on November 2021. The CORSYM 2021 theme, Nurturing Future Corrosionist for Better Corrosion Mitigation, covered key topics such as corrosion and inhibitors, corrosion of biomaterials, top of line corrosion, H2S and CO2 corrosion, coatings and composites for biomedical devices, electrochemical testing techniques, advanced materials and coatings, corrosion in concrete structures, welding and hot Corrosion, corrosion in ships and marine structures, corrosion of biomaterials, corrosion Under insulation, digitalization in corrosion. The contributions introduce numerous exciting ideas that spur novel research directions and foster multidisciplinary collaborations between various specialists in the field of corrosion engineering.

Author: Fumio Hine
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 248

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Book Description

Author: Yimin Zeng
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 206

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Book Description

Author: Edward Ghali
Publisher: John Wiley & Sons
ISBN: 0470024038
Category : Science
Languages : en
Pages : 574

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Book Description
Corrosion Prevention and Protection: Practical Solutions presents a functional approach to the various forms of corrosion, such as uniform corrosion, pitting corrosion, crevice corrosion, galvanic corrosion, stress corrosion, hydrogen-induced damage, sulphide stress cracking, erosion-corrosion, and corrosion fatigue in various industrial environments. The book is split into two parts. The first, consisting of five chapters: Introduction and Principles (Fundamentals) of Corrosion Corrosion Testing, Detection, Monitoring and Failure Analysis Regulations, Specifications and Safety Materials: Metals, Alloys, Steels and Plastics Corrosion Economics and Corrosion Management The second part of the book consists of two chapters which present: a discussion of corrosion reactions, media, active and active-passive corrosion behaviour and the various forms of corrosion, a collection of case histories and practical solutions which span a wide range of industrial problems in a variety of frequently encountered environments, including statues & monuments, corrosion problems in metallurgical and mineral processing plants, boilers, heat exchangers and cooling towers, aluminum and copper alloys, galvanized steel structures as well as hydrogeological environmental corrosion This text is relevant to researchers and practitioners, engineers and chemists, working in corrosion in industry, government laboratories and academia. It is also suitable as a course text for engineering students as well as libraries related to chemical and chemical engineering institutes and research departments.

Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1134

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Book Description

Author: Ruishu Feng
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The electrochemical corrosion behaviors of high strength low alloy carbon steel, Grade S-135, and ultra-high strength low alloy carbon steel, Grade UD-165, were investigated in alkaline brines at pH of 7.9, 10.7, and 12.4 and four H2S partial pressures (PH2S) from 0 to 69 kPa at 85 oC using in situ electrochemical measurements, ex situ surface analyses, and software modeling. HS-(aq) was calculated to be the dominant sulfide species from pH 7.9 to 12.4. After 60 hours, polarization resistance (Rpol) of S-135 and UD-165 generally increased as pH increased at lower PH2S (0 and 0.83 kPa), whereas Rpol decreased and then increased as pH increased at higher PH2S (8.3 and 69 kPa). At each pH, the lower PH2S increased Rpol or did not significantly change Rpol, whereas the higher PH2S decreased Rpol. Two opposite effects from H2S were proposed, an accelerating effect due to H2S(aq) and HS-(aq) facilitating the Faradaic reactions and the localized corrosion, and an inhibiting effect due to the protectiveness of the corrosion products. The inhibiting effect was often observed at relatively low H2S concentrations at pH 7.9 and 12.4. The electrochemical impedance did not change significantly at different stir rates for both S-135 and UD-165, indicating that mass transport in the bulk solution was not the rate determining step. The corrosion products generally changed from iron carbonate and sulfides to iron oxide as pH increased, which agreed with the Pourbaix diagrams. Solution pH in the three solutions were calculated to be 8.1, 9.8, and 10.8 at 200 oC, respectively. Polarization resistance values of UD-165 at 200 °C were consistently one to two orders of magnitude lower than at 85 °C, which corresponded to a drastic increase in corrosion rate at elevated temperature. At 200 °C, Rpol at 9.8 was the smallest after 60 hours among the three solutions. The modeled results were in reasonable agreement with the experimental CR values within a factor of 4. A new method derived from the generalized Butler-Volmer equation allowed to obtain anodic Tafel slopes from LSV even with the effect of limiting current. At 200 oC, the ba values indicated that the anodic reactions followed the Bockris mechanism at pH 8.1 and a two-electron mechanism at pH 9.8 and 10.8. As pH increased, the major corrosion products changed from pyrrhotite/siderite to magnetite although the corrosion products were a mixture of iron carbonate, sulfide and oxide. At 4 °C and 10 MPa total pressure, experimental results for two drill steels, Grade S-135 and Grade UD-165, showed a distinct drop in corrosion rate when transitioning from sweet (CO2) corrosion to sour (H2S) corrosion in 5% wt. NaCl brine. It was found that a CO2:H2S ratio as high as 1000 was still enough for sour corrosion to dominate the conditions tested. The CO2+H2S condition and H2S condition had the similar anodic and cathodic Tafel slopes, which were smaller than the CO2 condition. The presence of H2S could have caused the formation of FeS(s) at the steel surface where the pH and Fe2+(aq) concentration might be higher than in the bulk solution.